Adjustable mechanism



Nov. 17, 1942. L A MCNAB 2,302,134

ADJUSTABLE MECHANISM Filed Sept. 3, 1940 7 I I 6 Y 6 IN ENTER LULIIE A. PYENABE Patented Nov. 17, 1942 ADJUSTABLE MECHANISM Louis A. McNabb, Evanston, Ill., assignor to The Bell & Howell Company, Chicago, 111., a. corporation of Illinois Application September 3, 1940, Serial No. 355,109

Claims.

My invention relates particularly to adjustable support mechanism which is adapted for use as a tilt support for picture projectors.

The general object of the invention resides in the provision of a novel, effective and convenient adjustable mechanism, particularly adjustable support mechanism, which is well adapted for use as a tilt support for picture projectors, and which is susceptible of unobtrusiveness Without sacrificing convenience in manipulation, the invention contemplating a picture projector for home use on which unobtrusive mechanical devices are desirable.

With this object in View, my invention consists in certain features of novelty in the construction, combination and arrangement of parts by which the said object and certain other objects, hereinafter appearing, are effected, all as fully described with reference to the accompanying drawing and more particularly pointed out in the appended claims.

In the said drawing- Figure 1 is a partial front elevation of a picture projector embodying my invention, with parts broken away and shown in section;

Figure 2 is a partial sectional View substantially on the line 22 of Figure 1; and

Figures 3 and 4 are partial sectional views substantially on the line 3-3 of Figure 1 and showing parts in different positions.

Referring to the drawing, a frame structure is provided by an enclosing casing or cabinet I within which a mechanism frame 2 is secured. Parallel vertically disposed supporting legs 3 are spaced transversely of the casing and are slidably mounted in vertical bearings 4 of the frame 2 and within the frame structure, and extend downwardly through openings 5 through the bottom of the casing to variably extend downwardly from the frame structure. The lower ends of the legs are provided with enlarged feet 6 engageable upwardly against washers 1 on the bottom of the casing to limit upward or retracting movement of the legs. See particularly Figures 1 and 2.

A shaft 8 is rotatably mounted on the frame 2 and within the frame structure, and is disposed on a horizontal axis extending transversely of the legs 3. The legs 3 are provided with longitudinally extending gear racks 9, and gear pinions II on the ends of the shaft 8 mesh with these racks for effecting simultaneous longitudinal movement of the legs with rotation of the shaft.

A vertical wall of the casing l extending correspondingly with and adjacent the shaft 8 is provided with a circular opening I2 thereinto, the shaft thus extending transversely of this opening. A second shaft 13 is mounted for rotation and axial movement in a bore M of the frame 2 and within the frame structure on an axis extending centrally through the opening [2 and transversely of the shaft 8. A radially extending circular manipulating knob I5 is secured on the outer end of the shaft l3, and is positionable with axial movement of this shaft in or exterior of the opening [2, as shown respectively in Figures 3 and 4. The knob l5 limits inward movement of the shaft 13, and a thrust collar l6, secured on the inner end of this shaft, is engageable with the frame 2 to limit outward movement of this shaft.

The shaft [3 is provided with a helical selflocking gear worm i! which meshes with a helical worm gear I8 on the shaft 8 for rotation of this shaft and actuation of the legs 3 with rotationof the shaft [3.

The feet 6 of the legs 3, being engaged downwardly on a supporting surface, such as a table top, to support the frame structure, the legs 3 are yieldably urged upwardly with respect to the frame structure by the weight of the frame structure, and the helical gears I! and 18 are arranged so that the leg members, as so yieldably urged, thrust the shaft [3 and with it the manipulating knob I5 outwardly, as shown in Figure 4, until the thrust collar 16 engages against the frame 2, thus positioning the knob 15 outwardly of the opening 12 for convenient manipulation thereof, the self-locking worm gear l1 maintaining the legs in outwardly extending adjusted position. However, engagement of the feet 6 of the legs 3 upwardly against the washers l of the casing l at the retracted position of the legs 3, terminates the aforesaid yielding urge of the legs 3, in which case the shaft 13 may be rotated in the direction to position it inwardly and to position the knob l5 in the opening 12, as shown in Figure 3, where it is unobtrusive and is not likely to be damaged.

The knob 15 is provided with a manipulating formation inwardly of the exterior axial face thereof for conveniently rotating it and the shaft I3 to position the knob exterior of the opening I2, which manipulating portion consists of a di ametrical rib I9 formed by diametrically opposite recesses 2| in the exterior axial face of the knob.

While I have thus described my invention, I do not wish to be limited to the precise details described, as changes may be readily made without departing from the spirit of my invention, but having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

1. In a mechanism of the character described, the combination with a frame structure provided with an opening thereinto, of a member mounted on said frame structure for rotation and axial movement on an axis extending through said opening and provided with a manipulating portion positionable with axial movement thereof in or exterior of said opening, an additional member movably mounted on said frame structure and yieldably urged in one direction, meshed helical gears respectively connected with said movable members and including a self-locking worm angularly and axially fixed with said first mentioned movable member, said gears being arranged to thrust said first mentioned movable member in the direction outwardly of said opening under yieldable urge of said second movable member, shoulder means limiting movement of said second movable member in its yieldably 'urged direction, and a second shoulder means limiting axial movement of said first mentioned movable member.

2. In a mechanism of the character described, the combination with a frame structure provided with a circular opening thereinto, of a member mounted on said frame structure for rotation and axial movement on an axis extending centrally through said opening and provided with a radially extending circular manipulating portion positiontable with axial movement thereof in or exterior of said opening, said manipulating portion being provided with a manipulating forma tion inwardly of the exterior axial face thereof, an additional member rotatably mounted on said frame structure on an axis transverse to the axis of said first mentioned rotatable member and yieldably urged in one direction, meshed helical gears respectively fixed with said rotatable members including a self-locking worm angularly and axially fixed with said first mentioned rotatable member, said gears being arranged to thrust said first mentioned rotatable member in the direction outwardly of said opening under yieldable urge of said second rotatable member,

shoulder means limiting rotation of said second rotatable member in its yieldably urged direction, and a second shoulder means limiting axial movement of said first mentioned rotatable member.

3. In an adjustable supporting mechanism, the combination with an enclosing frame structure provided with an opening thereinto, of a member mounted within said frame structure for rotation and axial movement on an axis extending through said opening and provided with a manipulating portion positionable with axial movement thereof in or exterior of said opening, a supporting leg member movably mounted within said frame structure to variably extend therefrom, and cooperating elements respectively connected with said rotatable and leg members and operative to actuate said leg member with rotation of said rotatable member and to permit axial movement of said rotatable member.

4. In an adjustable supporting mechanism, the combination with an enclosing frame structure provided with an opening thereinto, of a member mounted within said frame structure for rotation and axial movement on an axis extending through said opening and provided with an outer manipulating portion positionable with axial movement thereof in or exterior of said opening, a supporting leg member movably mounted within said frame structure to variably extend downwardly therefrom, meshed helical-gears respectively connected with said rotatable and leg members and including a self-locking worm angularly and axially fixed with said rotatable member, said gears being arranged to thrust said rotatable member in the direction outwardly of said opening with pressure applied upwardly on said leg member, and means limiting axial movement of said rotatable member.

5. In an adjustable supporting mechanism, the combination with an enclosing frame structure provided with a side opening thereinto, of a pair of vertically disposed supporting legs spaced transversely of said opening and movably mounted within said frame structure to variably extend downwardly therefrom and provided with longitudinally extending gear racks, a shaft rotatably mounted within said frame structure and extending transversely of said legs and said opening and provided with gear pinions meshing with said racks, a manipulating member mounted within said frame structure for rotation and axial movement on an axis extending through said opening and transversely of said shaft and provided with an outer manipulating portion positionable with axial movement thereof in or, exterior of said opening, meshed helical gears respectively fixed with said shaft and manipulating member including a self-locking worm angularly and axially fixed with said manipulating member, said helical gears being arranged to thrust in the direction outwardly of said opening with pressure applied upwardly on said leg members, and means limiting axial movement of said manipulating member.

LOUIS A. McNABB. 

